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1.
J Dairy Sci ; 104(12): 12600-12615, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34419272

RESUMEN

The objective of this study was to investigate the effects of partial substitution of corn silage (CS) with sweet sorghum silage (SS) in the diets of lactating dairy cows on dry matter (DM) intake, milk yield and composition, blood biochemistry, and ruminal fermentation and microbial community. Thirty mid-lactation Holstein dairy cows [mean ± standard deviation; 639 ± 42.0 kg of body weight; 112 ± 24.0 d in milk (DIM)] were assigned to 3 groups (n = 10/treatment) by considering parity, milk yield, and DIM. The cows were fed ad libitum total mixed rations containing 55% forage and 45% concentrate, with only the proportion of CS and SS varying in 3 treatments (DM basis): SS0 (0% substitution of CS), 40% CS and 0% SS; SS25 (25% substitution of CS), 30% CS and 10% SS; and SS50 (50% substitution of CS), 20% CS and 20% SS. Dry matter intake and milk protein concentration tended to linearly decrease with increasing proportion of SS in the diet. Yields of milk (mean ± standard deviation, 30.9 ± 1.12 kg/d), 4% fat-corrected milk (30.0 ± 0.81 kg/d), energy-corrected milk, milk protein, lactose, and total solids, concentrations of milk fat, lactose, somatic cell counts, and milk efficiency did not differ among diets. The concentrations in blood of urea nitrogen, phosphorus, aspartate aminotransferase, and malondialdehyde linearly increased with increasing SS proportion. Blood IgA decreased with increasing SS substitution rate, but blood IgG and IgM were not different among diets. Ruminal pH did not differ among diets, whereas ruminal NH3-N concentration quadratically changed such that it was greater for SS50 than for SS0 and SS25. Molar proportions of propionate and acetate to propionate ratio were less for SS25 than for SS0. Although the diversity and general ruminal microbial community structure were not altered by partially replacing CS with SS, the relative abundances of predominant bacteria were affected by diets at the phylum and genus levels. Firmicutes and Bacteroidetes were dominant phyla in the ruminal bacterial community for all diets, and their relative abundance linearly decreased and increased, respectively, with increasing SS substitution rate. Prevotella_1 and Ruminococcaceae_NK4A214_group were detected as the most and the second most abundant genera, with their relative abundance linearly increased and decreased, respectively, with increasing SS substitution rate. The relative abundance of Fibrobacter linearly increased with increasing dietary SS proportion, with greater abundance observed for SS25 and SS50 than for SS0. These results suggest that substitution of CS with SS altered the relative abundances of some predominant bacteria; however, these changes had little effect on ruminal fermentation and milk yield. Under the current experimental conditions, substituting up to 50% of CS with SS had no negative effects on milk yield, indicating that SS can partially replace CS in the diets of high-producing lactating dairy cows without adding extra grain, when diets are fed for a short time. As the effects of substituting CS with SS depend upon the chemical composition and digestibility of these silages and the nutrient requirements of the cows, additional grain may be required in some cases to compensate for the lower starch content of SS.


Asunto(s)
Alimentación Animal , Microbiota , Ensilaje , Sorghum , Zea mays , Animales , Bovinos , Industria Lechera , Dieta/veterinaria , Digestión , Ingestión de Alimentos , Femenino , Fermentación , Lactancia , Rumen/metabolismo , Ensilaje/análisis
2.
Animal ; 15(3): 100146, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33573957

RESUMEN

Ruminants can tolerate moderate concentrations of dietary tannin, making it feasible to replace corn with sorghum in ruminant diets; however, conditioning temperature of pelleted total mixed ration (PTMR) greatly affects nutrient digestibility. The objective was to determine effects of grain type and conditioning temperature during pelleting on growth performance, ruminal fermentation, meat quality and blood metabolites of fattening lambs. This was a 2 × 3 factorial study, with corn and sorghum and three conditioning temperatures (65, 75 and 85 °C) in a randomized complete design, with 36 lambs (120 ±â€¯10.2 d and 24.9 ±â€¯3.3 kg) grouped by weight and randomly allocated. The resulting six PTMRs were referred to as 65-S, 75-S and 85-S for sorghum-based diets, and 65-C, 75-C and 85-C for corn-based diets, for low, medium and high pelleting temperatures, respectively. There was no grain type × conditioning temperature (Grain × Temp) interaction on growth performance and apparent nutrient digestibility. Furthermore, grain type did not affect DM intake (DMI), average daily gain (ADG) or feed conversion ratio (FCR) of fattening lambs. Pelleting at 75 °C improved ADG (P < 0.03) and FCR (P < 0.02) of fattening lambs compared to other temperatures. There was a Grain × Temp interaction (P < 0.01) on ruminal pH (lowest in lambs fed 75-S). There tended (P = 0.07) to be a Grain × Temp interaction for total volatile fatty acid (VFA), and there were Grain × Temp interactions for molar proportions of acetate (P < 0.04), butyrate (P < 0.03) and branch-chained VFA (P < 0.01). Lambs fed sorghum-based PTMR had greater molar proportion of propionate (P < 0.03) and lower acetate to propionate ratio (A:P, P < 0.04). Lambs fed sorghum-based PTMR had higher plasma concentrations of urea nitrogen (N) (P < 0.03), glucose (P < 0.01) and alkaline phosphatase (P < 0.05), whereas other blood metabolites were not affected by treatments. There were Grain × Temp (P < 0.03) interactions for color coordinates of longissimus and mid-gluteal muscle. Lambs fed sorghum-based PTMR had lower (P < 0.01) dressing percentage and meat quality than those fed corn-based PTMR. We concluded that sorghum can replace corn in lamb diets without compromising growth performance and feed efficiency; furthermore, feeding sorghum vs corn improved rumen fermentation, with reduced A:P ratio and enhanced N and glucose utilization. Finally, pelleting at 75 °C increased feeding value of either sorghum- or corn-based PTMR for fattening lambs.


Asunto(s)
Alimentación Animal , Rumen , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Digestión , Fermentación , Carne , Rumen/metabolismo , Ovinos , Temperatura , Zea mays
3.
ISA Trans ; 109: 389-400, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33069374

RESUMEN

Only vision-based navigation is the key of cost reduction and widespread application of indoor mobile robot. Consider the unpredictable nature of artificial environments, deep learning techniques can be used to perform navigation with its strong ability to abstract image features. In this paper, we proposed a low-cost way of only vision-based perception to realize indoor mobile robot navigation, converting the problem of visual navigation to scene classification. Existing related research based on deep scene classification network has lower accuracy and brings more computational burden. Additionally, the navigation system has not yet been fully assessed in the previous work. Therefore, we designed a shallow convolutional neural network (CNN) with higher scene classification accuracy and efficiency to process images captured by a monocular camera. Besides, we proposed an adaptive weighted control (AWC) algorithm and combined with regular control (RC) to improve the robot's motion performance. We demonstrated the capability and robustness of the proposed navigation method by performing extensive experiments in both static and dynamic unknown environments. The qualitative and quantitative results showed that the system performs better compared to previous related work in unknown environments.

4.
Animal ; 13(3): 509-517, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29986789

RESUMEN

The gastrointestinal tract (GIT) of animals is capable of sensing various kinds of nutrients via G-protein coupled receptor-mediated signaling transduction pathways, and the process is known as 'gut nutrient chemosensing'. GPR40, GPR41, GPR43 and GPR119 are chemoreceptors for free fatty acids (FFAs) and lipid derivatives, but they are not well studied in small ruminants. The objective of this study is to determine the expression of GPR40, GPR41, GPR43 and GPR119 along the GIT of kid goats under supplemental feeding (S) v. grazing (G) during early development. In total, 44 kid goats (initial weight 1.35±0.12 kg) were slaughtered for sampling (rumen, abomasum, duodenum, jejunum, ileum, cecum, colon and rectum) between days 0 and 70. The expression of GPR41 and GPR43 were measured at both mRNA and protein levels, whereas GPR40 and GPR119 were assayed at protein level only. The effects of age and feeding system on their expression were variable depending upon GIT segments, chemoreceptors and expression level (mRNA or protein), and sometimes feeding system × age interactions (P0.05) on GPR43 expression; and there were no feeding system×age interactions (P>0.05) on GPR41 and GPR43 protein expression. The expression of GPR41 and GPR43 in rumen and abomasum linearly (P<0.01) increased with increasing age (from days 0 to 70). Meanwhile, age was the main factor affecting GPR40 expression throughout the GIT. These outcomes indicate that age and feeding system are the two factors affecting chemoreceptors for FFAs and lipid derivatives expression in the GIT of kids goats, and S enhanced the expression of chemoreceptors for FFAs, whereas G gave rise to greater expression of chemoreceptors for lipid derivatives. Our results suggest that enhanced expression of chemoreceptors for FFAs might be one of the benefits of early supplemental feeding offered to young ruminants during early development.


Asunto(s)
Dieta/veterinaria , Ácidos Grasos no Esterificados/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Cabras/fisiología , Receptores Acoplados a Proteínas G/fisiología , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Tracto Gastrointestinal/metabolismo , ARN Mensajero/metabolismo , Transducción de Señal
5.
J Biol Regul Homeost Agents ; 32(4): 951-957, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30043583

RESUMEN

In this study of Th17/Treg cells, the therapeutic effect of Astragalus glycoprotein on collagen-induced arthritis in mice (CIA) was explored, and a basis for the clinical treatment of rheumatoid arthritis is provided. Sixty mice were selected for the establishment of a CIA mouse model, and were then randomly divided into a CIA model group, a hydrocortisone control group, a low, medium, and high dose group of Astragalus glycoprotein, respectively. The same number of control groups with same number of mice was established and after basic immunization, intraperitoneal injections were given once daily for two weeks in the treatment. At the end of the treatment, the mice in each group were selected and the proportion of Th17/Treg cells was detected by flow cytometry. The expression and positive expression of RORt, Foxp3, P-STAT3 and P-STAT5 protein were detected by Western blot and immunohistochemistry. Astragalus glycoprotein was shown to potentially improve the diet and mental state, reduce the arthritis index score and improve the pathological state of synovial membranes in the mice. Moreover, flow cytometry results showed that, compared with the CIA model group, the proportion of Th17 cells in the four other groups of mice decreased, while the proportion of Treg cells increased. This difference was statistically significant (P less than 0.05). From the experiment, the following conclusions were drawn: Astragalus glycoprotein can reduce Th17 cells and their transcription factors in the peripheral blood of CIA mice, up-regulate Treg cells and their transcription factors, and correct the balance of Th17/Treg cells so as to achieve an effective of treatment for CIA mice.


Asunto(s)
Artritis Experimental/inmunología , Artritis Reumatoide/inmunología , Saponinas/farmacología , Linfocitos T Reguladores/efectos de los fármacos , Células Th17/efectos de los fármacos , Animales , Artritis Experimental/tratamiento farmacológico , Astragalus propinquus , Masculino , Ratones , Ratones Endogámicos BALB C , Extractos Vegetales/farmacología , Linfocitos T Reguladores/inmunología , Células Th17/inmunología
6.
SAR QSAR Environ Res ; 26(4): 279-300, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25906044

RESUMEN

Bruton's tyrosine kinase (BTK) plays a crucial role in B-cell activation and development, and has emerged as a new molecular target for the treatment of autoimmune diseases and B-cell malignancies. In this study, two- and three-dimensional quantitative structure-activity relationship (2D and 3D-QSAR) analyses were performed on a series of pyridine and pyrimidine-based BTK inhibitors by means of genetic algorithm optimized multivariate adaptive regression spline (GA-MARS) and comparative molecular similarity index analysis (CoMSIA) methods. Here, we propose a modified MARS algorithm to develop 2D-QSAR models. The top ranked models showed satisfactory statistical results (2D-QSAR: Q(2) = 0.884, r(2) = 0.929, r(2)pred = 0.878; 3D-QSAR: q(2) = 0.616, r(2) = 0.987, r(2)pred = 0.905). Key descriptors selected by 2D-QSAR were in good agreement with the conclusions of 3D-QSAR, and the 3D-CoMSIA contour maps facilitated interpretation of the structure-activity relationship. A new molecular database was generated by molecular fragment replacement (MFR) and further evaluated with GA-MARS and CoMSIA prediction. Twenty-five pyridine and pyrimidine derivatives as novel potential BTK inhibitors were finally selected for further study. These results also demonstrated that our method can be a very efficient tool for the discovery of novel potent BTK inhibitors.


Asunto(s)
Proteínas Tirosina Quinasas/antagonistas & inhibidores , Piridinas/química , Pirimidinas/química , Relación Estructura-Actividad Cuantitativa , Agammaglobulinemia Tirosina Quinasa , Algoritmos , Bases de Datos de Compuestos Químicos , Modelos Moleculares , Proteínas Tirosina Quinasas/química , Análisis de Regresión
7.
SAR QSAR Environ Res ; 24(10): 795-817, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23941641

RESUMEN

Cyclin-dependent kinase 2 (CDK2) has been identified as an important target for developing novel anticancer agents. Molecular docking, three-dimensional quantitative structure-activity relationship (3D-QSAR) and pharmacophore modelling were combined with the ultimate goal of studying the structure-activity relationship of CDK2 inhibitors. The comparative molecular similarity indices analysis (CoMSIA) model constructed based on a set of 3-aminopyrazole derivatives as CDK2 inhibitors gave statistically significant results (q (2) = 0.700; r (2) = 0.982). A HypoGen pharmacophore model, constructed using diverse CDK2 inhibitors, also showed significant statistics ([Formula: see text]Cost = 61.483; RMSD = 0.53; Correlation coefficient = 0.98). The small residues and error values between the estimated and experimental activities of the training and test set compounds proved their strong capability of activity prediction. The structural insights obtained from these two models were consistent with each other. The pharmacophore model summarized the important pharmacophoric features required for protein-ligand binding. The 3D contour maps in combination with the comprehensive pharmacophoric features helped to better interpret the structure-activity relationship. The results will be beneficial for the discovery and design of novel CDK2 inhibitors. The simplicity of this approach provides expansion to its applicability in optimizing other classes of small molecular CDK2 inhibitors.


Asunto(s)
Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Relación Estructura-Actividad Cuantitativa , Antineoplásicos/química , Antineoplásicos/farmacología , Humanos , Simulación del Acoplamiento Molecular , Pirazoles/química , Pirazoles/farmacología
8.
Anim Reprod Sci ; 137(3-4): 177-82, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23395360

RESUMEN

The objective of this study was to examine the effects of maternal protein or energy restriction during late gestation on postnatal fetal growth and visceral organ mass of goats. Eighty pregnant goats with similar age (2.0 ± 0.3 yr) and body weight (BW, 20.0 ± 1.0 kg before pregnancy) were assigned to 3 dietary treatments during late gestation: control (CON), 40% protein restricted (PR) and 40% energy restricted (ER) diets until parturition, after which offspring received normal diets for nutritional recovery. Kids were killed and visceral tissues were harvested at birth and week 6. Maternal protein or energy restriction decreased (P < 0.05) birth weight, and the weights of thymus, heart, abomasums, small intestine. The length of fetus from PR and ER were all decreased (P < 0.05) compared with that from control. When expressed relative to BW, thymus and small intestine for PR and ER still remained less (P < 0.05) than that for control. After 6 weeks of nutritional recovery, there was no difference (P = 0.91) in BW among groups; the kids from nutritional restriction groups showed a greater (P < 0.05) growth rate compared with kids from CON. Moreover, liver (only in ER, P < 0.10) and kidney (only in ER, P < 0.05) were proportionally increased to BW at week 6. The results indicate that maternal protein or energy restriction programs the fetal growth in goats, particularly the proportional responses of fetal organs relative to BW, including thymus, small intestine, kidney and liver.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Dieta con Restricción de Proteínas/veterinaria , Cabras/embriología , Cabras/metabolismo , Fenómenos Fisiologicos Nutricionales Maternos/fisiología , Animales , Animales Recién Nacidos , Peso al Nacer/fisiología , Femenino , Desarrollo Fetal/fisiología , Análisis de los Mínimos Cuadrados , Masculino , Tamaño de los Órganos , Embarazo
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